The present invention relates to a double switch, automatic warning system for trailer hitches and, in particular, to a novel trailer hitch ball structure providing an indication of a faulty coupling or unauthorized removal of the hitch from the trailer.
Trailers hitched to towing vehicles conventionally use a ball and socket hitch type arrangement. The ball is included as part of an automotive hitch mount secured to the rear bumper or frame of the vehicle, and cooperates with a socket coupling member attached to the trailer. A properly designed coupling will permit the trailer to be maneuvered by the towing vehicle while maintaining a tight connection between the ball and socket using a latch mechanism, which in a locking position, prevents uncoupling of the socket member from the ball member when the trailer is being towed.
However, many conventional coupling devices presently in use on the highways present a potential hazard because of the tendency of the socket to become loose from the ball due to improper coupling, rough traveling conditions, or wear and tear on the connection. Failure of the coupling will result in accidents which cause personal property damage and other severe injury. Normally the driver of the vehicle is unaware that the coupling is loose until the coupling is loose until the coupling actually separates. A further shortcoming of the prior art permits unauthorized uncoupling of the trailer hitch resulting in loss of property without suitable safeguards or warnings.
Various attempts have been made to provide safety features and warning devices for vehicles which are hitched using a ball and socket type coupling including a number of patents which provide either visual or audible warnings when a coupling becomes loose. Prior art patents relating to this type of arrangement are described in applicant's own patent (4,593,264) as well as U.S. Pat. Nos. to Quillici et al. (3,710,270) and Gehman et al. (4,627,633), among others.
The present invention provides a double switch safety system for a ball and socket type trailer coupling which uses a first switch in the top of the ball which will provide an indication that the socket has become loose or has been removed from the ball, and a second switch in the base of the ball which will become actuated if the nut which holds the ball onto the towing vehicle frame structure becomes loose.
Among the objects of the present invention are to provide a warning system for ball and socket type trailer hitches which will provide a signal to the towing vehicle driver when the ball and socket coupling becomes loose or when the ball bends or otherwise separates from the towing vehicle frame to permit the driver to slow down and stop the vehicle before an actual separation of the coupling takes place.
Another object is to provide a trailer hitch coupling which provides a warning if the hitch is removed without authorization.
These and other objects of the invention will become apparent with reference to the following drawings and specifications.